It is clear, then, that the earth must be at the centre and immovable, not only for the reasons already given, but also because heavy bodies forcibly thrown quite straight upward return to the point from which they started, even if they are thrown to an infinite distance. From these considerations then it is clear that the earth does not move and does not lie elsewhere than at the centre.

It is simplicity that makes the uneducated more effective than the educated when addressing popular audiences.

All paid jobs absorb and degrade the mind.

A friend is simply one soul in two bodies.

The true forms of government, therefore, are those in which the one, or the few, or the many, govern with a view to the common interest; but governments which rule with a view to the private interest, whether of the one or of the few, or of the many, are perversions. For the members of a state, if they are truly citizens, ought to participate in its advantages.

I have gained this from philosophy: that I do without being commanded what others do only from fear of the law.

The quality of life is determined by its activities.